1. Field of the Invention
The present invention generally relates to a spray nozzle and more specifically to improvements in the spray nozzle disclosed in my U.S. Pat. No. 5,076,497 issued Dec. 31, 1991. The improved spray nozzle functions in a manner similar to the nozzle disclosed in that patent but includes a novel and unique structure to provide a more effective diffusion pattern of liquid discharge. The improved spray nozzle is a two piece structure screw connected together including a metal fitting connected to and in communication with a pressurized liquid supply pipe and a one piece injection molded plastic nozzle, preferably but not limited to nylon, screw connected to the metal fitting. The nozzle includes laterally spaced longitudinal side walls interconnected by a top wall and open at the bottom to form a continuous bottom slot. The slot extends throughout the length of the nozzle and is provided with a diffuser plate or blade at the discharge end thereof that is integral with the top wall of the nozzle. The inner surfaces of the side walls of the nozzle are vertically parallel and at any given point are spaced equally from a longitudinal center line of the nozzle.
Another significant improvement incorporated into the nozzle of this invention is the longitudinal convergence of the inner surfaces of the side walls from the inlet end of the nozzle toward the diffuser blade or plate at the discharge end. Each side wall converges toward the center line of the nozzle. A further significant improvement of the improved spray nozzle of this invention is to provide interchangeable metal fittings having different size orifices to enable control of the quantity of liquid being discharged by changing metal fittings rather than necessitating that a user have available a supply of one-piece cast spray nozzles in order to control the volume of discharge of liquid into the spray pattern. Likewise interchangeable nozzles are provided having different angles of convergence to vary the spray pattern of the liquid. An angle of convergence ranging between 1° to 3° from a centerline of the nozzle may be provided. A nozzle with the angle of convergence of 2° is preferred when a metal fitting with a smaller orifice is utilized and a nozzle having an angle of convergence of 1° is preferred when a metal fitting with a larger orifice is used. A further significant improvement in the spray nozzle of this invention is the provision of a thin metal insert in the slot in the bottom of the nozzle. The end of the insert adjacent the metal fitting includes an opening in the rearward end directly below the orifice in the metal fitting when the nozzle is assembled onto the metal fitting. The inner surface of the side walls of the nozzle each have a groove receiving the side edges of the metal plate. The outer end of the metal plate terminates adjacent to but in spaced relation of the lower end of the diffuser blade at the discharge end of the nozzle. This structure allows air to be drawn in at the rear of the nozzle for more through mixing of air and liquid as the air and liquid travel through the enclosed area formed by the top wall and side walls of the nozzle and the metal insert in the bottom slot.
2. Description of the Prior Art
The spray nozzle disclosed in my U.S. Pat. No. 5,076,497 is constructed of one piece cast metal and thus includes a fixed diameter orifice or passageway into the nozzle or extension of inverted U-shaped configuration. The spaced vertical wall surfaces in the nozzle are longitudinally parallel and the surfaces must be very smooth in as much as any irregularities in these surfaces adversely affects the flow of liquid in the extension. Therefore, the cast wall surfaces in my prior spray nozzle must be polished or smoothed to remove irregularities formed during the casting process. Smoothing such surfaces is labor intensive and materially adds to the production cost of the nozzle. Additionally, in my prior spray nozzle, the diffuser plate or blade must be secured in place by drilling an aperture and placing a pin therein to secure the blade. Additionally, in order to prevent leakage around the blade where the upper end is slid into a notch in the upper wall of the nozzle, a sealant must be provided at the juncture between the edges of the notch and the surfaces of the blade. This procedure is also labor intensive. In addition, the spray nozzle in my prior patent mentioned above includes an orifice of fixed diameter supplying pressurized liquid to the nozzle thereby requiring the use of different spray nozzles when it is desired to change the volume of liquid in the spray pattern.